Milling machine



Dec 12, 1944. H. BLOOD ET AL 3 MILLING MACHINE Filed April 6, 1959 5sheets-sheet 1 INVENT OR. lau h 2000 7 BY flq/xs f/P/xsr ATTORNEY.

Dec. 12, 1944. L. H. BLOOD ETAL 2,365,043

MILLING MACHINE Filed April 6, 1939 5 Sheets-Sheet 2 .97 I INVENTOR.laws/54000 BY /7%w.s ffl/xsr ATTORNEY.

L. H BLOOD ET AL MILLING MACHINE Filed April 6, 1939 'Dec. 12, 1944.

5 Sheets-Sheet 5 A ORNEY.

Dec. 12, 1944- L. H. 1 31.000 ET AL MILLING MACHINE Filed April 6, 19395 Sheets-Sheet 5 INVENTOR.

loans/9.1520047 ATTORNEY.

Patented Dec. 12,

UNITED STATES PATENT QFFIE MILLING meme Louis n. Blood, Covington, Kyand Hans Ernst,

Cincinnati, Dhio, asaignors to The Cincinnati Milling Machine 00.,Cincinnathohio, a corporation of Ohio Application April 6, 1889,Serial'No. Blififihh 10 Claims.

This invention relates to machine tools and provide atransmission andcontrol mechanism which would ,render a small machine as flexible Y inautomatic cycle control as larger machines.

There is, however, a demand for a small milllug machine of the typeunder consideration for production manufacture of small parts, but inorder to be useful for such a purpose it is desirable that the machinehave automatic control to some degree.

' One of the objects of this invention is to pro-' vide a compactautomatic cycle control mechanism which may be incorporated in a smallmilling machine to yield any automatic cycle of which full-sizedmachines are capable.

\ AllOllhGl' object of this invention is to provide" a full automaticcycle bench miller with accurate automatic tripping mechanism wherebyvery small feed movements of the order of one-sixteenthof an inch becomeavailable.

A further object of this, invention is to provide an improved controlmechanism with a changeable automatic cycle control part for which otherparts may be substituted to yield different cycles.

.Other objects and advantages of the present invention should be readilyapparent ,by reference to the following specification, considered incon- Junction with the accompanying drawings form- 40 ing a part thereofand it is to be understood that any modifications may be made in theexact structural details there shown and described, within the scope ofthe appended claims, with- (CLQfl-tll V Figure 2 is a side elevation ofthe in shown in Figure l. s

Figure 3 is an expanded view of the table nsmission mechanism.

Figure 4 is a vertical section showing the v l mission mechanism for thecutter spindle as viewed on the line of Figure 3.

Figure 5 is an enlarged section on the line t-t of Figure 1 showing thedetails of the ratchet mechanism.

Figure 6 is a detail view showing one of the control cams and thedetentlng mechanism.

Figure '7 is a cross sectional view through aremovable program assemblyunit as viewed on the line l-l of Figure 1.

Figure t is a diagraatic view of the hydraulic control circuit. a

Figure '9 is a detail view of a latch dog.

In Figures 1 and 2 of the drawings there is 2 shown a front and sideelevation of the machine embodying the principles of this invention. Thecomplete machine isshown in Figure 2 in the form adaptable for mountingon a bench, .while in Figure l the machine is shown mounted on 2 aseparate bed. In these views the reference numeral it indicates the bedof the machine upon which is formed guideways ii for supporting thereciprocating work support or table l2. The bed of the machine isprovided with. an upstanding portion it upon which is formed guidewaysit for receiving a vertically adjustable spindle carrier ii. Thespindlecarrier has an overarm it fixedly attached thereto, whichisprovided on the underside with guideways i'l upon which a pendant is maybe-slidably adjusted and fixed in position. A cutter spindle is isrotatably supported in the spindle carrier and is bodily adlustabletherewith with respect to the surface of the table ii.

A common prime mover 10, shown in Figure 3, is provided for drivingthetable and the cutter spindle. The motor It drives, through gearing 2 l acommon drive shaft 22 which is shown more particularly in Figure 4. Thisshaft carries a gear but departing from or exceeding the spirit; of the23which actuates a first branch transmission for bodying the principlesof this invention.

driving the table; and a pair of bevel gears 24 and 25 which serve todrive the cutter spindle through a second branch transmission.

Referring more particularly to Figure 4, a

clutch member '26 is slidably mounted on the shaft 22, and is adapted tobe connected with the shaft by a hydraulic clutch which is indicated bythe reference numeral 21 in Figure 8. This clutch consists of a splitring 29 and a ring expanding member 30 which is radially actuated by ahydraulic piston 3| mounted in a cylinder 32 formed in the shaft 22.

By admitting fluid pressure to the cylinder the,

piston 3| is forced outward, thereby causing expansion of the ring 21into engagement with the interior of the clutch member 28. The clutchhas teeth 03 and 34 on opposite ends thereof for interengagement withcorresponding clutch teeth formed on opposing faces of the bevel gears24 and 20 for opposite rotation thereof. The bevel gears 2t and 25intermesh with a common bevel gear II which is attached to the end of avertical shaft 06 anti-frictionally supported in the bed Ill. The shaftis held against vertical movement but has a splined connection at 01with a splined shaft 00 which depends from the upper end of the spindlecarrier II. The shaft 30 is connected.

' by change gears, indicated generally by the reference numeral 00, to aparallel shaft 40 ,which carries a bevel pinion'li intermeshing with alarge bevel gear 42 splined on the end of the cutter spindle It. Thebevel gear 42 is supported on anti-friction bearings in the rear wall ofthe carrier and is held against axial movement while the splined portion00 of the spindle is is adapted to be moved axially of the bevel gear 42which permitsthe forward end of the spindle to be mounted in a quill M.

The forward end of the spindle is anti-fric-.

tionally ioumaled by bearings in the quill for 3 rotation relativethereto. The spindle transmission is provided with a hydraulic brakewhich is in Figure 8. The bed I0 is provided with a cylinder 41 in whichis reclprocably mounted a piston 40 adapted to engage a ball 40 insertedbetween the tapered ends of an expansion brake ring 00 which surroundsthe shaft 36. The ring is held against rotational movement by a fixedpinli. By introducing pressure into the cylinder through .port 52 thepiston 40 is urged in a diwhich is reclprocably .assao-is a drivingrelation between the shaft 02 and the tubular shaft 00.

The rapid traverse train is driven by the gear 54 which intermeshes witha gear II that drives gear 12 in one direction. The gear II is integralwith a sleeve 13 upon which is formed a second gear 14. The gear 14 isconnected through an.

intermediate idler gear I! for rotation of gear 10, which is supportedfor free rotation on a shaft 11, in a direction opposite to that of gearconnectible to the shaft through'individual friction disc clutchesindicated generally by the reference numerals 00 and-0 I.

It will be noted that the feed transmission is unidirectional andtherefore the table can only be fed in one direction, while the rapidtraverse transmission .terminates injoppositely driven indicatedgenerally by the reference numeral 40 a rection to cause the ball 40 tospread the ring- 00 out of engagement with the shaft 30 and upon releaseof pressure in the cylinder 41, the parts retract and the resiliency ofthe ring causes it to' contract and engage the shaft 00, therebyapplying a braking pressure thereto.

a The table transmission which is own in Figure 3 comprises a feed trainand rapid travthe larger gear of which interengages with the smallergear of the preceding couplet. The pin- .ion 00 of couplet 50 drivesgear II which is keyed to the end off-shaft 02. This shaft carries aclutch member 00 which drives one-half of the plates of a friction discclutch ll. The friction Theother disc clutch constitutes a feed ratecontrol clutch,

and the inner portion 00 of this clutch'is keyed to a tubular shaft 00which terminates in a gear table feed screw 08. A hydraulically actuatedmember 10 serves to cause'frictional engagement of the discs of theclutch and thereby establish members whereby the table can be moved atrapid traverse in either direction. The machine can, gf course, bearranged to have the uni-directional feed in the otherdirection bysubstitutinga lead' screw of opposite hand to the lead screw 00.

The feed control clutch l4 and the two rapid traverse control clutchesl0 and II are adapted to be hydraulically actuated, and to this end thetubular shaft is divided into cylinders by fixed plugs 02 and 03. Theseplugs are inserted in the interior of the tube in proper position andsecured thereto by diametrical-pins 04 which pass through the tube andthe plug. A pair of pistons 05 and 88 are mounted within the tubebetweenthe plugs 82 and II, and the'adiacent ends of these pistons engage adiametrical cross pin 01 which is connected to a clutch actuating ring0|.

The piston ll may, therefore, be said to slide in a cylinder 09, and thepiston 00 to slide in a cylinder 00. The fixed plugs 02 and 00 haveannular grooves 0| and 92 respectively which intercommunicate with ports00 and 04 formed in I the tubular sleeve and these ports, in turn, arein constant communication with annular grooves 05 and 08 formed in theperiphery of the sleeve. Fixed collector rings 01 and 00 surround thegrooves 90 and 00 and delivery channels 00 and I00 are connected tothese rings whereby the channels are always in communication with thecylinders during rotation of the shaft. The plugs 02 and I! each have anelongated groove I00 cut in its periphery to form a communicationchannel between the annular groove and the cylinder adjacent thereto. Itwill now be apparent that if pressure is connected tochannel 00 whilechannel I00 is connected to exhaust that the piston 05 will be forced tothe right as viewed in Figure 3 and effect engagement of the rapidtraverse clutch 00; while if the pressure is connected to the channel I0 while channel 00 is connected to exhaust the piston 00 will be movedto the left i as viewed in Figure 3 and effect engagement of 01' fordriving a gear 00 secured to the end of the clutch 0i and disengagementof clutch 00; Since these are friction disc clutches it will be aponeitherof the clutches 40 and II and they will, therefore, beautomatically disengaged.

The plug 33 also serves to form acylinder I02 in which is slidablymounted a piston I03 for actuation of a cross pin I04 which is connectedto the member 10 for actuation of the feed clutch.

Pressure is supplied to the cylinder I02 through a pipe I05 which isconnected to the collector ring 34 and annular groove I is formed in thetubular shaft opposit the pipe I for collecting'fluid and delivering itthrough radial bore I01 to cylinder I02. It will be obvious that whenpressure is admitted to the channel I05 that the feed clutch will beengaged, and when the channel I05 is connected to exhaust that the feedclutch will automatically disengage.

Referring to Figure 8, the channels 39, I00 and I05 are connected toports I08, I09 and 0 respectively, which are formed in a valve blockindicated generally by the reference numeral III and which is mounted onthe front of the machinevas shown in Figures 1 and 2. This valve blockhas pressure is admitted to channel m the ball check valve I31 opensandfluid is readily admitted to the lower end of the cylinder I30 to eifectrapid upward movement of the spindle carrier.

ahead of the piston is, however. forced into e passage I 30 due to theclosing of the ball check valve Ifll. The'fluid must then pass throughthe rate valve whichhas an annular groove ldil which is adapted tointerconnect the port I 38 with a port a bore H2 in which a pilot valveplunger H3 is ports I08 and I00; and a pair of annular grooves.

I20 and I2I which establish communication of ports I08 and I09 with theexhaust grooves H3 and I I1 respectively. Thus, in the position shown,

both of the rapid traverse clutches are disengaged.

The port IIO from the feed clutch communicates with a bore I22 in whichis slidably mounted a valve plunger I23 which is urged in one directionby a spring I24 and in the opposite direction by a cam I25. This plungerhas a central spool I23 for-disconnecting the pressure. groove H5 fromport H0; and an annular groove I21 on one sweet the spool for connectingthe port IIO, to

' the exhaust groove H8. Thus, in the position shown, the feed clutch isdisengaged and no motion will be transmitted to the table.

The spindle carrier I5 is adapted to be ved up and down a limited amountby hydraulic essure and to this end a lead screw I 28, which is threadedin the carrier, is provided on the upper end with a piston I23 which isreciprocable in a cylinder I formed in a block I3I that is integrallyattached to the upper end of the column I52 which is in directcommunication with the port I48. When the rate plunger M0 is cientlyelevated to reduce the hydraulic resist.- w 1 between port I33 and portIE2, the spindle can rier moves downward at a rapid rate. As the onmember I rotatesthe bell crank H2 in a could terclockwise direction therate control plunger l dd is moved downward to constrict the port Illand thereby retard the escape of fluid from the lower end of thecylinder I30.

This restriction is efiected by cutting ll-shaped grooves I53 in thespool I54 which normally would close the port Ht. It will now be evidentthat thes'pindle carrier may not be moved upward at a feed rate but maybe moved downward first at a rapid traverse'rate and then at a feedrate. The ports I34 and IE0 in the valve block III which form thetermini of channels l l and lld are alternately connectihle to pressu eand exhaust by the reversingvalve plunger Ilt which has acentral spoollit adapted to disconnect the pressure groove i It from ports Ill andlit when the plunger is in a central position. Annular grooves I55 andl5l' formed on opposite sides of the spool I55 serve to alternatelyconnect one of the ports I34, I to the pressure groove i it and the remaining portto one of the exhaust grooves. c plunger lill'iscontinuously urged in one direc-- tion by a spring ill and moved in theother direc= tion by a cam l Ill.

Aspreviously mentioned, a hydraulic clutch ww provided for connectingthe cutter spindle to the a spindle transmission ioractuation thereof ahydraulic hrake was also provided for stopping the spindle after theclutch was disengaged. he

shown in Figured, the spindle clutch lt is connected by a channel I50 toport Ill in the valve block Ill and the hydraulically actuated spindlebrake 45 is connected by channel ltd to port lllll in the valve block'lll. These two ports communicate with a single hore ill in which isreciprocably mounted a control valve plunger lllll which has a centralspool Itt "for disconnecting the pressure groove tit from both of theports,

I3. The cylinder I30 is provided at one end with v a port I32 which isconnected hychannel I33 to port I34 in the valve block III.

The other end of the cylinder has a port I35 which communicates with aninterdrilled passage I36. A ball check valve I31 is mounted in one endoi" this passage and the other end terminates in .a port I33 of a ratecontrol valve, having a plunger I 40 which is urged upward, as viewed inFigure 8, by aspring I. A bell crank lever I42 is pivotally mounted onthe block I3I and carries an adjustable screw I43 threaded in one .armfor engaging the end of the plunger, and a vvshaped end'I44 on the otherarm which rides ona cam member I45 carried by a block I45 attached tothe upper end of the piston rod I41. The block I3I has a port I48. towhich channel I43 is com and annular grooves l 51.and I08 on oppositesides thereof for alternately connecting the pressure groove to theseports, and the remaining port to exhaust. I

This plungeris urged in one direction by a spring I69 and in theopposite direction by a cam I10. The fee cam I25, the, rapid traversecontrol cam H5, he spindle carrier control cam ltd and a spindle clutchand brake control cam llt are all splined on a shaft I'll as shown inFig- 111'67.

The shall; I 'II and assembled cams constitute a program determiningunit wh ch is removable from the machine as aunit whereby otherpneassembled units maybe substituted therefor to eflect a diil'erentcycle of operation or the machine. As each event of a given program iscompleted, the program determining unit is indexed to institute the nextevent. The indexing is effected by the movable slides and a series offluid operable indexing plungers are provided so that regardless of theslide being moved, or its direction of movement it is possible to placedogs that willeifect an indexing movement when the particular slidemovement has been completed. In

other words, all of the trip instrumentalities act upon the indexingsystem-and this in turn causes the program determining unit to beadvanced step by step and thus institute the successive events in theprogram.

The shaft Ill, Figure 7, is provided with an integral shoulder I12 onone end, and a threaded nut I13 on the other end, and between these twoelements are assembled the various cams, spacers and ratchet wheels. Thecams are, of course, spaced apart in accordance with the spacing of thevalve plungers so that they will ride on the periphery of the cams, asshown in Figure 6, while the ratchet wheels Ill are spaced apart inaccordance with the spacing of the ratchet plungers I15, I18, Ill andI". A detent wheel I19 is keyed on the shaft I1 I and a spring presseddetent I80 is supported for engagement with the wheel, thereby holdingthe parts in various indexed positlons.

The shaft I'll is provided with journal portions I82 and I83 on oppositeends thereof for interengagement withsockets I -and I85 formed in theends of axially adjustable members I08. These members have knurled headsI81 by means of which the members may be moved. It will be noted fromFigure 7 that the ends of the sockets I84 and Ill have a portion of theside wall out away as indicated at I" whereby the journal portions mayb'emoved laterally into axial alignment with the sockets. When this hasbeen accomplished, the members I are moved toward one another, therebysecuring the shaft ill in proper position Y 'erating piungers. Toprevent accidental return of the bearing-members, spring pressed detentsI88 are provided which engage V'-shaped notches Ill formed on thebearing members. It will be noted that one side wall of the notches iscut away which makes it possible to withdraw the bearing members againstthe action of the detents when it is desired to remove the program,

determining units. 1

Each indexing plunger is of the construction shown'in Figure 5 andcomprises a cylindrical member Isl which has a'reduced-e'nd I02 sur- Iby continuously urging the same into-engagement with the periphery of aratchet wheel I'll.

The upper end of the member .IOI is also provided with an annular groove202 which is always in communication with a port 283. Between theannular groove 202 and the upper end of the member Isl is .a series ofaxially extending grooves lflrwhereby operating fluid entering theannular groove "2 may flow to the cylinder 205 and thereby exertpressure on the upper end of the ratchet plunger and urge it downward.

with respect to the various coopengages a'shoulder 201 formed at the endof the cylinder for limiting 'or determining the length of plungermovement. In other words, the end walls of the chamber 205 determine thestroke of the plunger and this stroke is always the same.

An important. feature of this invention is the variation in the numberof steps or events that it is possible to incorporate in one program. Asillustrative of what can be accomplished and this depends upon thestroke of the index plungers and the diameter of the ratchet wheels,provision has been made for obtaining as highas 24 steps orevents in'one cycle. This means that each indexing movement of shaft I1 I would bethrough an angle of 15 degrees and the ratchet wheels would be providedwith 24 teeth. As the number of events decrease the number of ratchetteeth will be decreased down to a limit of 13. It will be obvious thatfor 13 steps the angle of index would be between 27 and 28 degrees. Thefixed stroke of the index plunger is therefore limited to the equivalentof 28 degrees, which prevents the plunger from picking up two teeth when24 'teeth are provided.

On the other hand, if a ratchet wheelhad 12 teeth, the fixed stroke ofthe ratchet plunger would not be sumcinent to pick up the next toothbecause the angle between teeth inthat case would be '30 degrees.Therefore, between 12 steps and 7 steps the ratchet teeth are spaced toprovide two cycles per revolution of the shaft III; between 6 and 4steps the ratchet teeth' would be spaced to provide four cycles perrevolution of the shaft I18; for 3 steps the ratchet teeth would bespaced to provide 8 cycles and for 2 steps the ratchet teeth would bespaced to pro'-.

vide 12 cycles per-revolution of the shaft.

Since the ratchet wheels constitute part of the program determining unitit will be apparent that in making up one of these units that it is onlynecessary to provide the proper ratchet wheels in accordance with thenumber of'events that it A shoulder I on the upper end of the plunger flis desired to effect in one cycle.

.plungers are capable of three positions, each cam may be said to have acommon radius such as indicatedby the reference numeral Ill in ,Figure 6for holding the valve plunger in a central position, and then thisradius is increased to the dimension indicated by the reference numeral20! or decreased to the dimension indicated by the reference numeral 2|.on the dividing line between sectors to cause movement of the plunger,either up or down from its neutral position in accordance with therequirements of each station. It thus becomes possible to not only varythe number of steps or events in a given cycle, but also to vary thecollective eflects of the cams at each station of any cycle.

Each cam is provided with a keyway 1| I which may serve as a referencepoint for laying out the several cams composing a given assembly sothat. when assembled on the shaft I'II they will be in cooperativerelation with one another. The hydraulic operation of the indexinggplungers is controlled by dog actuated pilot valves. For instance theplungers I15 and I" are connected by channels H2 and H3 to ports 2 andMS of a pilot valve- 2". This valve has a plunger 2|! which isoperatively connected to a trip lever 2".

The end of this lever lies i the path of trip.

to the same upper position, it is not necessary to adjust the screw 223,but the downward movement of the spindle carrier may vary, and thisvariation is taken care of 'by adjusting the screw 2 l9 and then lockingit by a nut 22l. The plunger 2l'I has a central spool .222 which. islarger in diameter than opposing spools on opposite ends of the plungerwhereby after the spool 222 passes the central pressure port 223 it isself-actuated, the remainder of the stroke.

When the plunger is up, the pressure port 223. is connected to port 2 tocause actuation of less of the distance that the surface of the work 3is from the topof the table. When the machine is set up the screw I28 isrotated by means of a wrench applied to the square end 226 of the pistonrod to' initially adjust the spindle carrier and thereby the cutter sothat when the piston I29 is moved down the cutter will engage the workto' the proper depth.

The indexing. plungers I and H8 are connected by channels 221 and 228 toports 229 and 230 of pilot valves 27 and 232 respectively. The pilotvalve 2" has a plunger 233 which is adapted to be depressed by dogscarried-bythe table against the compression of a spring 234. This valvehas-a pressure port 235 and an ex-:

haust port 235. The spring 234 normally holds the plunger in a positionto connect the channel 221 to the exhaust port 236. When the plunger isdepressed the pressure port isconnected to channel 221 to causeoperation of the index plunger "5.. E

The valve 232 has a plunger 23! which is adapted to be depressed againstthe compression of spring 238 by trip dogs carried by the table.

. K '5 Since each trip plunger 233 and 231 effect the same result in thesense that they each cause indexing-of the program determining assemblyunit in one step, two plungers have been pro vided in connection withthe table, whereby one is utilized for actuation by successive dogsduring travel of the table in one direction and the other utilized foractuation by a separatev set oi dogs during travel of the table in theother direction and if all of the dogs are made in the form of latchdogs 'so as to be effective in only one direction, it will be apparentthat only two plungers are necessary. and that any number of indexingmovements may be effected by the table during either direction oftravel.

Referring to Figure 2. the control dogs foraotuating one plunger duringone direction of movement of the table maybe mounted in T- slot 242,while the dogs to be operative during the other directionof tablemovement may be mounted in the T-slot 243. i

A detail view of one form of latch dog is shown in Figure 9 andcomprises a fixed portion 244 and a pivoted portion 245, the pivotedportion having a heel .245which is effective to prevent rotation. in onedirection but does not interfere with rotation in the oppositedirection.

Attention is invited to the fact that it is not necessary to limit oneof the T-slots in the table to dogs controlling one direction of tablemovement, but ,such dogs might be mounted in either The spring normallyholds the plunger in a position to connect the port 230 to exhaust port239. When the plunger is depressed a pressure port. 240 is connected tochannel 230 to cause operation of the index plunger I18. 'I'his plungeralso has anoperative connection to a-manually operable control lever24!, which lever-is mounted on the front of the machine and is utilizedto start the cycle. Although the machine may be provided with acontinuously repeating cycle, it is usual on small machines to provide astop position at the end of each cycle so that the work may be changed.Thus, in order to start the next cycle it is necessary to manuallyoperate the lever 2 so as to index the program determining operationposition.

assembly into its first both T-slots. The chief advantage of this nd onewhich is believed to be novel with thisa second plunger whereby rapidsuccessive in-' dexing can be effected. Since neither dog interfereswith the setting of the other there is no problem of i nterfere'nce inpositioning the dogs toobtain rapid indexing.

Fluid is supplied to the hydraulic control circuit by a pump 24'! whichhas an intake 248 through which fluid is withdrawn from the reservoir249 and a delivery line 250 which has a first branch connection 25! toport 223 of the carrier control valve, and a second branch 252 which isconnected to port 253 of a set-up control valve plunger 254. The plunger254 has anannular groove 255 for connecting port 253 to the pressuregroove N6 of valve block Ill.

The plunger 254 is provided with a longitudinally extending groove 253on one side which terminates at one end in the annular groove 255; and asecond longitudinal groove 251 located diametrically opposite the groove255 which does not run out at either end.

When'the plungeris raised by rotating the manually operable knob 258thegroove 256 serves to maintain pressure connection between the port 253and section ll6a of pressure groove 8; while the groove 251 connects thremainder of groove H5 to the reservoir groove H8.

This means that no pressure can be supplied to the plungers H3 and I23which control the feed and rapid traverse clutches and therefore shouldthe cam assembly be removed irom the machine .with pressure still'in thesystem the table would not-start to move.

Since the source of iiuid pressure is not cut on from plungers I65 andI54 it is still possible to operatethe vertical spindle'carrier,or'rotate the spindle for set-up purposes and since the trip lever m isstill effective for indexing purposes, it

'will be apparent that the program determining unit may still be indexedwithout causing feeding movement of the table.

An interlock has been provided to safeguard against movement of thespindle carrier while the table is feeding comprising a branch line 258from channel III! to an hydraulic spindle carrier clamp 259. Thus, whenpressure III! to cause engagement of the feed clutch, the spindlecarrier is clamped against movement.

' A relief valve 260 is connected to delivery channel 252 to limit thepressure velope'd in the system.

There has thus been pr vided a transmission and control mechanismsuitable for a small milling machine, said transmission having a minimumnumber of .control members compatible with essential requirements forselective cyclic control; and said control mechanism comprising compactremovable program determining units adapted to cooperate with a commonpilot control circuit and indexing means whereby with a minimum amountof mechanism incorporated in the machine, it is possible to obtain alarge number of different operating cycles or programs.

We claim:

1. In a milling machine having a work table and a spindle carrier, thecombination of a mechanical transmission for effecting movement of thetable including a plurality of fluid operable clutches for controllingthe rate and direction of movement thereof, a plurality of cam operatedcontrol valves for controlling said clutches, said cams being operatedto control actuation of said clutches in a predetermined cyclic order,and a pilot control circuit for indexing said cams including pilotvalves associated with the table and spindle carrier for trip operationthereby.

2'. In a milling machine having a support, a work table and a spindlecarrier mounted on the support for relative movement in two directions,the combination with a prime mover, o! a series of fluid operabledevices selectively energizable for connecting said prime mover to causerelative movement betweenthe supports including rate and directionclutches, a valve block mounted in said support, a series of valves insaid block for controlling fluid operation of said devices havingoperating portions projecting from said block, a source of fluidpressure connected to said valves, 9. cycle program determining assemblyremovably mounted in the support and having spaced cams engageable withthe respective portions for operation 01' said control valves,

resiliently operable means for maintaining said portions in engagementwith the respective cams, fluid operabl ratchet means for rotating saidassembly intermittently to cause operation of the machine in accordancewith said predetermined program, and trip operable valves associatedwith the table and carrier for controlling fluid operation of saidratchet means.

3. In a machine tool having a tooi'support and a work support, thecombination oi a mechanical transmission for moving one said supports,hydraulic transmission for moving the other of said supports, saidmechanical transmission having a plurality of fluid operable clutchesfor controlling the rate anddirection of on of said supports, aplurality of control valves ior controlling the position of saidclutches, other control valves for controlling operation of saidhydraulic transmission, an indexible cycle control unit removably thatcan be 'del is in channel determining the position of all of said valvesand thereby the collective eflect 01' said transmissions, a source offluid pressure connected to said valves, fluid operable ratchet plungersfor indexing said unit, and a series of trip operable pilot valvesconnected to the respective plungers for controlling actuation thereof,said pilot valves being associated with the respective supports wherebyeither support may control operation of the other support.

4. In a machine tool having a cutter support and a work support, thecombination oi transmission means for effecting relative movementbetween the supports including fluid operable rate and directionclutches, a source of fluid pressure for actuating said clutches,control valves for selectively connecting said source of pressure tosaid clutches, an indexible self-contained unit removably mounted in themachine and having means for actuating the several valves, said unithaving a predetermined number 01' stations per revolution forcontrolling one or more cycles of operation of the machine,

means carried by the unit for determining its station angle and therebythe number of machine, cycles effected per revolution, 9. series offluid operable indexing plungers for said unit, said plungers having aconstant length of stroke whereby they are effective over apredetermined range or station angles. i

5. In a machine tool having a tool support and a work support, thecombinations! a first transmission for moving one of said supportsincluding a plurality of fluid operable control clutches, a secondtransmission for moving the other of said supports including fluidoperable means, a plurality of control valves for the respective fluidoperable devices, a sourceor fluid pressure for supplying said valves,an indexible cycle control 4 unit having motion transmitting connectionsmounted in said machine and carrying means for u with each of saidvalves whereby successive po sitions of said unit will produce diflerentcollective eflects on said transmission, and means to disconnect saidsource of pressure from certain of said valves to prevent operation orone or said transmissions.

6. In an automatic cycle control mechanismfor a machine tool having apair of relatively movable supports and separate transmission means formoving each support, the combination of a series of valve members forcontrolling the eflect of each transmission, a source of fluid pressureconnected to each or said valve members, a program determiningmnithaving contoured members individual to the respective control valves fordetermining the position thereof, resiliently operable means formaintaining said valves in engagement with the periphery of saidcontoured members whereby said valves may be moved to any one of threepositions and trip controlled fluid operable means for indexing saidprogram control unit.

7. In a machine tool having a cutter support and a work support, thecombination or transmission means (or eflectingrelative movement betweenthe supports including rate and direction determinators, an indexibleprogram determining unit having a plurality of stations, means at eachstation/for controlling operation or said determinators includingmeans-to produce a feeding movement at one station and a rapid traversemovement at the next station, fluid operable ratcheting means forindexing said unit, a pair 1 of trip operable pilot valves associatedwith one or said supports and operativsly connected for assumescontrolling actuation of different ratcheting means and dog meanscarried by the. support and arranged for independently actuating saidplungers during unidirectional movement of the support whereby theplungers may be operated in rapid succession to produce a short feedmovement.

8. In an automatic cycle control mechanism for the transmission means ofa machinetool, said transmission means having a plurality of fluidoperable control members, the combination of a series of valve membersfor controlling fluid actuation of the control members, a programdetermining unit comprising a shaft and a plurality of cams attachedthereto, said shaft having Jo'urnal portions at opposite ends, socketbearings in the machine for receiving said portions to rotatably supportthe cams in opposition to said valve members, resiliently operable meansfor maintaining said valve members in contact with sion when the unit isremoved from the machine said cams, said valve members having a centralinoperative position and control positions on either side thereof, asource of pressure connected to said valve members, and means forstopping the flow of fluid pressure to said valve members when theprogram determining unit is removed from the machine.

9. In an automatic cycle control mechanism for a machine tool having atable transmission, a tool support and fluid operable means foractuating the tool support, the combination of a source of pressure, afirst series of valve members for controlling the flow of pressure tosaid fluid operable means, said table transmission having a plurality.of fluid actuable control parts, a second series of valve members forcontrolling the admission or pressure to said parts, a proand releasessaid valves.

10. In a milling machine having a table, a spindle carrier, a toolspindle Journaled in the carrier, a combination with transmission meansfor driving said parts including a rapid traverse determinator, a feeddeterminator; a start and stop control clutch for the. spindle, a poweroperable brake for the spindle and an actuator for the spindle carrier,of a source ot power for actuating said parts including individualcontrol members for the respective parts for connecting said source ofpower to effect actuation thereof, a common controller operativelyconnected to all of said control members, said controller beingindexable irom station to station, individual means carried by thecontroller for simultaneously determining the position or all 01' saidcontrol members at a given station, and means trip operable by the tableor spindle carrier to eflect indexing of said control.

LOUIS H. BLOOD.

HANS ERNST.

